Pathfinder
Editor, Senior Moderator
Zika epidemic and associated severe outcomes: ECDC publishes updated risk assessment
10 Mar 2016
The Zika epidemic in the Americas continues to evolve and expand geographically. There is now strong evidence of an association between Zika virus infection during pregnancy and congenital central nervous system malformations as well as between Zika virus infection and Guillain–Barr? syndrome. Over the past two months, autochthonous cases of Zika virus infection were reported in 39 countries or territories worldwide.
Zika virus and pregnancy
At present, there is no evidence which stages of pregnancy are most vulnerable to Zika virus. Therefore the entire duration of pregnancy should be considered at risk, concludes the risk assessment published today. Pregnant women and women who are planning to become pregnant should consider postponing non-essential travel to affected areas until after delivery. The evidence in favour of a causal link between transplacental infection and congenital central nervous system (CNS) malformations is substantial and accumulating. It is still uncertain how many pregnant women who become infected will transmit the virus to the foetus, and how many foetuses will develop brain damage or other malformations. It is likely that the risk of transplacental infection as well as the risk of developing congenital CNS malformations depends on the gestational age at the time of infection. It is also plausible that other risk factors, such as the mother’s age and nutritional status, also influence the risk of transplacental transmission, but there are currently no data available to explore such risk factors.
Zika virus and Guillain–Barr? syndrome
Cases of Guillain–Barr? syndrome (GBS) continue to be reported from the affected countries. GBS is also known to be associated with other infectious diseases that are prevalent in the Americas and the Caribbean. Since October 2015, five countries or territories have reported increased GBS incidence.
Sexual transmission
The presence of infectious Zika virus in semen has been detected up to three weeks after onset of disease. The longest interval reported between the onset of symptoms in a male and the subsequent onset of the disease thought to be due to sexual transmission in a female partner is 19 days.
Several cases of sexual transmission from males to their partners have been reported or are under investigation in recent weeks. So far, no sexual transmission of Zika virus from infected women to their partners and from persons who are asymptomatically infected have been reported. The role of asymptomatic males in the sexual transmission to women is unknown.
Risk of establishment of local vector-borne transmission in Europe
The risk of transmission of Zika virus infection in Europe is variable and depends on several co-factors, for example:
EU/EEA Member States should consider mitigation measures, such as advising travellers visiting affected countries to take measures to prevent mosquito bites, as well as enhancing vigilance towards the early detection of imported cases of Zika virus in infections in the EU.
The rapid risk assessment also includes options on risk mitigation concerning substances of human origin, disease surveillance and outbreak preparedness.
Read the risk assessment:
Rapid Risk Assessment: Zika virus disease epidemic: potential association with microcephaly and Guillain–Barr? syndrome. Fourth update
Read more:
Zika epidemic in the Americas and Caribbean
Countries and territories with local Zika transmission
Mosquito maps
http://ecdc.europa.eu/en/press/news/...es%2FNews.aspx
10 Mar 2016
The Zika epidemic in the Americas continues to evolve and expand geographically. There is now strong evidence of an association between Zika virus infection during pregnancy and congenital central nervous system malformations as well as between Zika virus infection and Guillain–Barr? syndrome. Over the past two months, autochthonous cases of Zika virus infection were reported in 39 countries or territories worldwide.
Zika virus and pregnancy
At present, there is no evidence which stages of pregnancy are most vulnerable to Zika virus. Therefore the entire duration of pregnancy should be considered at risk, concludes the risk assessment published today. Pregnant women and women who are planning to become pregnant should consider postponing non-essential travel to affected areas until after delivery. The evidence in favour of a causal link between transplacental infection and congenital central nervous system (CNS) malformations is substantial and accumulating. It is still uncertain how many pregnant women who become infected will transmit the virus to the foetus, and how many foetuses will develop brain damage or other malformations. It is likely that the risk of transplacental infection as well as the risk of developing congenital CNS malformations depends on the gestational age at the time of infection. It is also plausible that other risk factors, such as the mother’s age and nutritional status, also influence the risk of transplacental transmission, but there are currently no data available to explore such risk factors.
Zika virus and Guillain–Barr? syndrome
Cases of Guillain–Barr? syndrome (GBS) continue to be reported from the affected countries. GBS is also known to be associated with other infectious diseases that are prevalent in the Americas and the Caribbean. Since October 2015, five countries or territories have reported increased GBS incidence.
Sexual transmission
The presence of infectious Zika virus in semen has been detected up to three weeks after onset of disease. The longest interval reported between the onset of symptoms in a male and the subsequent onset of the disease thought to be due to sexual transmission in a female partner is 19 days.
Several cases of sexual transmission from males to their partners have been reported or are under investigation in recent weeks. So far, no sexual transmission of Zika virus from infected women to their partners and from persons who are asymptomatically infected have been reported. The role of asymptomatic males in the sexual transmission to women is unknown.
Risk of establishment of local vector-borne transmission in Europe
The risk of transmission of Zika virus infection in Europe is variable and depends on several co-factors, for example:
- The presence of a potential mosquito vector; Zika virus disease is caused by a virus transmitted to humans by Aedes mosquitoes, especially by the Aedes aegypti species.
- The competence of Aedes albopictus to transmit Zika virus, which depends on characteristics of the pathogen (strain-specific vector competence) and of the mosquito species;
- The capacity of the vector to transmit the infection is determined by a number of factors such as vector competence, the mosquito population density, feeding host preferences, biting rates and survival of the mosquito population.
EU/EEA Member States should consider mitigation measures, such as advising travellers visiting affected countries to take measures to prevent mosquito bites, as well as enhancing vigilance towards the early detection of imported cases of Zika virus in infections in the EU.
The rapid risk assessment also includes options on risk mitigation concerning substances of human origin, disease surveillance and outbreak preparedness.
Read the risk assessment:
Rapid Risk Assessment: Zika virus disease epidemic: potential association with microcephaly and Guillain–Barr? syndrome. Fourth updateRead more:
Zika epidemic in the Americas and Caribbean
Countries and territories with local Zika transmission
Mosquito maps
http://ecdc.europa.eu/en/press/news/...es%2FNews.aspx